Technical Field
The present invention relates to an image processing device, an imaging device, an image processing method, and an computer readable medium.
Related Art
Digital cameras are widely known that are provided with autofocus, in which phase difference detection methods and contrast detection methods are employed, and also what is referred to as a manual focus mode, in which a user can manually perform focus adjustment.
Digital cameras including a manual focus mode are known in which a reflex mirror is provided to enable focus adjustment while checking an imaging subject, and a method is utilized in which a split microprism screen is employed to display the phase difference visually. Utilization of a method in which contrast is checked visually is also known.
However, in digital cameras with the reflex mirror omitted that have become prevalent in recent years, since there is no reflex mirror, there is no method to check the subject-image while displaying the phase difference, and contrast detection methods have had to be relied on. However, in such cases, contrast cannot be displayed at a resolution greater than that of the display device, such as a Liquid Crystal Display (LCD), requiring adoption of methods such as enlarging a portion for display.
In recent years, therefore, a split-image is displayed within a live-view image (also referred to as a through image), so as to make the work of focusing on the imaging subject easier for the user when in manual focus mode. Split-image used herein refers to a divided image that has been divided into two, for example (such as each image divided in the up-down direction) in which there is misalignment in the parallax generation direction (such as the left-right direction) according to focus misalignment, and is a split-image to remove the misalignment in the parallax generation direction from the in-focus state. An operator (such a photographer) operates a manual focus ring to match the focus so that misalignment of the split-image (such as each image divided in the up-down direction) is removed.
In the imaging device described in Japanese Patent Application Laid-Open (JP-A) No. 2009-147665 (hereafter referred to as Patent Document 1), out of light rays from an imaging optical system, a first subject-image and a second subject-image formed by light rays divided by a pupil divider are each photoelectrically converted to generate a first image and a second image. The first and the second images are employed to generate a split-image, and a third subject-image formed by the light rays not divided by the pupil divider are photoelectrically converted to generate a third image. The third image is displayed on a display and the generated split-image is displayed inside the third image, and color data extracted from the third image is applied to the split-image. By applying color data extracted from the third image to the split-image in this way, excellent visibility of the split-image can be achieved.
An image processing device described in JP-A No. 2000-078607 (hereafter referred to as Patent Document 2) includes a color balance adjustment processing means that adjusts color balance in an image signal input from an image input device. The color balance adjustment processing means estimates from an image signal the chromaticity of an illumination light source when the image of the image signal was acquired, and adjusts the color balance of the image signal based on the estimated chromaticity of the illumination light source.
Technical Problem
However, in the imaging device of Patent Document 1, the color characteristics of the display colors of the third images and the color characteristics of the display colors of the split-images are sometimes similar. In such cases, an issue arises in which it becomes difficult to make a visual check of a boundary line between the third image and the split-image.
Moreover, when the image processing device described in Patent Document 2 is employed to perform color balance adjustment of the split-image and images other than the split-image (such as a background image), an issue arises in which it becomes difficult to make a visual check of boundary line between the image other than the split-image and the split-image.